Evaluate XPath expressions on a target XML document.
The <xpath> element allows a business process to evaluate XPath expressions on a target XML document.
When the <xpath> element executes, the source stream is processed into an XPath document and then the XPath expressions are evaluated in sequence. The BPL runtime engine automatically manages the lifetime of the documents and caches them to allowing processing to be as efficient as possible
Each prefixmappings entry is defined as a prefix, a space, and then the URI to which that prefix maps. This is especially useful if the document defines a default namespace with the xmlns="http://somenamespaceuri" syntax, but does not supply an explicit prefix mapping. The following prefixmappings string would map the myprefix prefix to the http://somenamespaceuri URI. Note the space character in the string:
The BPL <xpath> element is intended to support XPath expressions which yield a scalar value, that is a single piece of text, number, date etc. It is not intended to deal with expressions that yield an XPath DOM. This means that if the expression does yield a DOM, the target property will not be updated. DOM programming is beyond the scope of BPL. If your business needs such processing, then the XPath should be performed in a code block or a call to a utility class.